Brake apparatus.



D. L LINDQUIST. BRAKE APPARATUS. 111 1101111011 FILED 12.5, 1911.

1,041,642. Patented Oct. 15,1912.

GUM Meg untransTA'rEs PATENT OFFECE.

DAVID L. LINDQUISTQ or yonxnns; 'Ew YORK, ASSIG-INOR T0 o'rrs nnnvaros 1 COMPANY, Oil? JERSEY CITY, JERSEY, A CORPORATION OF NEW JERSEY;

BRAKE APPARATUS.

Specification of Letters Patent.

Application filed April 5, 1911. Serial No. 619,069.

' To all whom it may concern:

Be it .known that I, DAVID L. Lmooursr, a subject of the King of Sweden, residing at Yonkers, in t-liefcoi'inty of Westchester and State of New York, have invented a new anduseful Improvement in Brake Apparatus, of which the following is a specifica'tion. v

My invention relates to brake-controlling apparatus and may be considered as a modification of or an improvement on the brakecontrolling mechanism disclosed in the patent to John Boyce, 814,669, March 18, 1906, for elevator brakes.

Anarrang'eirient like that shown in the patenta'hove named has been found some instances and under some conditions of op-',

eration objectionable for'the reason that it places the control of the brake too much in the hands o'ftlie operator, permitting the brake to begapplied with too much power under ordinary operating conditions.

An objector my invention is to provide in connection with an electromagnetic brake,

as used" in'ya n elevator controlling system, means for preventing the brake from being applied with full powerin thenormal stopping ofzth'e motor,- said means being auto; .1 mat-it: inoperation and independent of the operation of the car controller. Other objects of the invention undthe exact nature; thereofwill appear hereinafter. r The accompanyin drawing is a diagram- .matic view of an eevator car, motor, and controlling apparatus. 1 The -hrakc. apparatus as conventionall shown comprises a brake shoe 1, a brake coil} 2, magnet core 3 and a brake applying spring 4 lyhen the brake coil 2 receives; current, the brake shoe 1 is lifted against the tension of thespring 4. The bi'zikcjuagnet whenenergized not only lifts'the brake but also opens. the switch 5 inshuntwith a resistance'ti. The system of control r01 the motor: comprises potential switch P, revcrsingswitches "it and R; an accelerating magnet M, starting resistance S, upper limit switches 66,. b, c, and ,lower limit switches a, b, a. Current is supplied from the positive and negative mains, designated. and connected to any s'uilahlesoumpotcurrent supply. When the potential s i r'h' is closed a holding circuit therefor is i-sizih lishcd as follows: from the positive main through the wire 7, potential switch magnet coil 8, wire 9, limit switch 0, wire 10, limit switch 0, wire 11, car safety switch 12in the car C, and wire 13 to the minus' main. If the car switch K is thrown, for example,

cuit forthe reversing switch R is established as follows: from the 'versing switch R, con uctor 17 limit switch a', wire 18, contact l t, car switch K. and conductors l9 and 20 to the negative main. The reversing switch R operates to lift the bridging contacts 21, 22, into engagement with the cooperating stationary contactsmicl establishes circuits for the motor armature A and a motor shunt field coil The armature circuit may be? traced from the positive main through conductor 15, con.

22, 31, conductor 32, starting resistance S. and conductor 20 to the negativcnuiin. The circuit for the shunt positive main through the conductors 15, through contact 24: to 21, through conductors 3 33, 34, shunt fieldcoil 23 and conductors and 20 to the negative main. "lhc brzalre -magnet also receives current and lifts the brakcas will be fully set forth hereinafter;

mg resistance in s'eries'with the mason-4 it runs. at slow speed. 'lheaccclcrating magnet M being connected as usual across the motor armature r ceives a gradually in- V crcasingcurrent as the armature speeds up.

tuined through the brake magnet and resistance 39 inlseries therewith. This (Motor-42, resistance-59, switch 5, brake magnet coil .2, and conductors 43 and 13 to the'nnnus mam. The resistance 39 is such rent,.- i.Y1Slllfi(l8Dt3l3O vlift the brake .a reversing switch 191 operated however, the I'PQISlZHMT: J lS shortcir iuited and the brake coil receives the full line potential so find to the right, to engage the contact 14, a cir-' tact-s 24, 21, 25, conductorslfi. 2?. armature brush 28, through the armature A,- brush 29. conductor 30, reversing switch contacts 30.

field coil is from the;

motor is at rest a circuitis normally main winding circuit may be traced as follows: fronithe" POSIUVQHHIHI through conductor-40, limit-f V switch b, conductor-e1, limit SWlltfh a, con

that-the brake. coil only receives a weak cur- 'Wh'en...

Patented oet. is, 1912;

positive main through the conductor 15, magnet coil.16 of the re @As the motor reccives'currciit u'ith the start ioa llO

the brake is lifted. The brake circuit established by the operation of the reversing switch It is as follows: from the positive main through the conductor 15, reversing switch contacts Ql, 21, wires 33 and t4, switch 5, brake coil 2, wires 43 and 13 to the negative main.

To stop the motor the car switch K is brought back to central position, thereby opening the circuitthrough the reversing switch magnet and causing the reversing switch R to open. The current supply is thereby out 01f from the motor armature. The short circuit for the resistance 39 is also opened at the reversing switch contacts 21 and As the brake when lifted holds the switch 5 open, the resistances 6 and 39 are now both in series with the brake coil. The resistance (5 is quite high, so that the current through the brake coil is reduced to a small value and permits the brake to be applied immediately with considerable power. The application oi the brake however permits the switch 5 to close and short circuit the resistance G leaving only the resistance 30 in series with the brake coil. The current through the brake coil is therefore increased and cases off the brake somewhat, but maintains suthcient pressure thereon to bring the motor smoothly and quickly to rest. It should be noted in this connection that when the brake is lifted, a comparatively small holding current. is required. It is therefore ofimportance to have a comparatively high resistance 6 initially in the brake circuit to insure the brake being applied. It will be observed that the operation of this means for preventing a too powerful application of the brake is independent of the car controller K, that is, it operates automatically and the brake cannot be applied with full power by any manipulations oi the car controller. In

' case of an emergency the operator may open the car safety switch 12, thereby opening the circuit through the potential switch magnet and causing the potential switch to open. This cuts off all current from the motor and opens the brake magnet circuit so that the brake is applied with full power to bring the motor quickly to rest. The opening of the potential switch also brings the back contacts 50 and 51 into engagement with the stationary contacts 52 and 53, respectively, and establishes a local circuit across the armature. This circuit may be traced from the brush 2.) through conductors 30, 54. resistance 55, contacts 53, 51, 50, 52, conductors 56 and 27, to the brush 28]"This circuit per- =nits a dynamic braking current through the armature which operates in the usual way Copies of this patent may be obtained for live cents each, by (beating th Washington, D. 0."

to assist in stopping the motor. It the car is permitted to travel beyond its normal limits the limit switches are operated to antomatically bring the car to rest. In going up, for example, the limit switches a, b and c are operated in succession. The switch a opens the reversing switch magnet circuit and has the same effect as the opening of the car switch. The opening of the switch 1) opens the brake magnet circuit and permits the brake to be applied with full power. The switch 0 serves to open the potential switch with the result above noted. Ordinarily the car will be brought to rest before all of the switches have opened.

To start the car down the controller switch K is moved to the left thereby establishing a circuit for the reversing switch R. The operation is similar to that already described except that the direction of current through the armature is reversed.

What I claim as new and desire to secure by Letters Patent of the United States is 1. The combination with an electric motor, of a. brake, a manual device for controlling the supply of current to the motor, means for applying the brake with full power, and means for automatically applying the brake with a reduced power whenever the said manual device is moved into position to cut oil' the supply of current from the motor.

2. The combination of an electric motor, a manual controller therefor, an electromagnetic brake, circuits for the brake magnet winding independent of said controller, and means associated with one of said circuits for effecting the application of the brake with a reduced power when the controller is operated to cut olt current from the motor.

3. The combination of an electric motor,- a manual controlling device therefor, an electric brake, and means independent of said manual controlling dcvicefor automatically easing ott' the brake during the stopping of the motor.

4. The combination of an electric motor, manual controlling means therefor, an elec tro'responsive brake, means independent of said controlling means to automatically apply the brake with a reduced power during the normal stopping of the motor, and additional means to effect the application ofihe brake with full power.

, In testimony whereof, I have signed my name to this specification in the presence-of two subscribing witnesses.

DAVID l.. LINDQUIST.

Witnesses:

EDWARD H. S'FICFLR,

Gnonos D. Rose.

Commissioner of Potentl, 

